Lipo battery issue running in series

[Lbizzle]

I recently had a lipo battery give me a issue. one cell is fluctuating really bad either really high when charging or really low when running. SMC is going to replace the battery due to its still really new. But they told me running batteries in series is not ideal. They said better to run one 6s vs two 3s due to basically it bad for the batteries and shortness there life. I’ll provide there link they sent me for you all to read your self. I just wanted to know if anyone else has this issue? I did this due to want to be able to run the same packs in my sct and not have a pack for every rc. Gives me more options running this way thanks for the help!!

https://www.smc-racing.net/index.php?route=product/category&path=166

 

[Headbangerfacerip]

They only say that cause its hard to balance all six cells when they are two sets of three. It really shouldn't matter how you run them as long as the cells are balanced together and they don't need to pick up the slack from a lazy one.

 

[slfmde]

I recently had a lipo battery give me a issue. one cell is fluctuating really bad either really high when charging or really low when running. SMC is going to replace the battery due to its still really new. But they told me running batteries in series is not ideal. They said better to run one 6s vs two 3s due to basically it bad for the batteries and shortness there life. I’ll provide there link they sent me for you all to read your self. I just wanted to know if anyone else has this issue? I did this due to want to be able to run the same packs in my sct and not have a pack for every rc. Gives me more options running this way thanks for the help!!

https://www.smc-racing.net/index.php?route=product/category&path=166

How much fluctuation are you seeing? I have 4 new SMC packs and see maybe .05 difference after running using a single 4s pack.

 

[Lbizzle]

This is while charging, the other pack is the identical one bought at the same time

 

[slfmde]

View attachment 16531
This is while charging, the other pack is the identical one bought at the same time

I assumed this was normal all 4 of my 2-3wk old SMC do this.

 

[Lbizzle]

I assumed this was normal all 4 of my 2-3wk old SMC do this.

Idk I got 3 other packs my self 2 - 2s 6500mAh and a 3s 5000mAh smc. All 3 packs are over 2 years old balance perfect. Got a buddy with a matching set his are still fine as well. His packs are about 1-1/2 years old. Only difference is this is the first time I’m running them in series. Are you running your packs in series?

 

[slfmde]

Idk I got 3 other packs my self 2 - 2s 6500mAh and a 3s 5000mAh smc. All 3 packs are over 2 years old balance perfect. Got a buddy with a matching set his are still fine as well. His packs are about 1-1/2 years old. Only difference is this is the first time I’m running them in series. Are you running your packs in series?

No just running a single pack at a time. Two are 4s and two 3s. Hmm I will keep a closer eye on them and see how it goes.

 

[jrwalte]

If you run 2 3s then you should always keep those 2 3s together and always run them together. This is so they age similarly. As a battery ages from time or usage, its internal resistance increases. If you keep using 1 3s for single use and not the other, then they can get out of alignment with each other and the older one will make the newer one discharge morer and prematurely ruin the newer one.

It's easier to just run 1 6s rather than keeping an eye on two separate 3s. You can also then replace the stock dual connector with a single connector which will reduce the resistance to the ESC.

 

[olds97_lss]

If you run 2 3s then you should always keep those 2 3s together and always run them together. This is so they age similarly. As a battery ages from time or usage, its internal resistance increases. If you keep using 1 3s for single use and not the other, then they can get out of alignment with each other and the older one will make the newer one discharge morer and prematurely ruin the newer one.

I didn't realize that... I figured if you always balance charged packs, and cycled them all the same, and storage charged them all the same, then you could use thing singly or as pairs without issue. Might explain why a couple of my first 9K 2S packs are getting sketchy. For the first few months, I always ran the same pairs in the same rig at the same time. Then I got a truck that ran only 1 pack and I'd run it, break something or just run out of time, then storage charge the unused pack back down to storage voltage while storage charging the used pack back up to storage voltage. So, one pack saw more real car time use than the other. Now one of them is taking 30+ minutes longer to balance even when ran as a pair in the same rig. I never bothered to keep track which one I used because even if I don't use a pack after charging it, I put it back down to storage voltage using the charge at the end of the day.

So, I guess it would be best to dedicate half my packs to single pack use and the other half to dual pack in series use to avoid causing them to get out of sync.

That will be more doable now that I have a dedicated charger to keep in my car when I'm out bashing. Before, I just charged all 12 of my packs, then if my day ended early, I'd discharge the unused ones in storage mode on the charger and I'd use whichever pack in whichever truck either singly or in series.